The present invention relates to a novel and useful valve mechanism which is especially useful in a fire extinguisher.
Dry chemical fire extinguishers are usually employed to extinguish fires by pressing a lever on the exterior of the fire extinguisher. The lever, in turn, opens a valve in the interior of the fire extinguisher to release pressurized dry chemical material. Dry chemical agents such as sodium bicarbonate, possess a fineness which leaves a residual powder in the vicinity of the valve seat. Consequently, the valve is not capable of resealing without thorough cleaning of the valve seat. Where the fire extinguisher has been employed to extinguish a fire, cleaning the valve component is not normally a problem since the de-pressurized condition of the extinguisher is indicated by a gauge. However, in certain situations, many fire extinguishers are used minimally through tampering or by casual movement of the fire extinguisher lever. Although a very small amount of chemical may be expelled in this process, the dry chemical agent will foul the valve seat preventing closure of the valve. Eventually, pressure inside the extinguisher will slowly leak to inactive the fire extinguisher and render it useless in fighting a fire.
A fire extinguisher valve which is capable of reseating or resealing after expulsion of dry chemical agents would be an advance in the fire control field.